Fig. 1: Dry state oligomerisation of nucleoside 2′,3′-cyclic phosphates catalysed by amino acids.

a RNA catalyses the formation of proteins from amino acids in the ribosome (grey). Our findings connect both molecule classes in an opposite catalytic direction at an earlier stage: amino acids catalyse the formation of RNA (red). b Concentrations of the oligomers of different lengths are plotted on a log scale for cCMP, cAMP, cUMP, and cGMP oligomerisation. With amino acids, the length-dependent concentrations are enhanced at least 100-fold, especially for bases A and C and around 10-fold for U. cGMP yields long oligomers already without amino acids. Controls without amino acids are shown in black (no aa), and amino acid-promoted reactions (corresponding three-lettered codes) are shown in other colours. Representative error bands (S.D.) are shown; for detailed errors, see Fig. S4. c The %-yields of the oligomers. The yields of RNA oligomerisation for different amino acids and nucleotides are calculated as the sum of nucleotides in oligomer form, i.e. the concentration of oligomers times their respective length. The shaded region highlights hydrophobic amino acids, with aliphatic chains shown in black, and all other amino acids are shown in grey. The data for no aa controls is visualised as a horizontal black line, indicating the many-fold increase of the overall yield. The effect of amino acid mixtures on RNA oligomerisation is presented in Fig. S5. All reactions were performed at 25 °C with 10 mM cNMP and 50 mM amino acid in 10 µl, at pH 10 for 20 h, and yields were quantified by reverse phase HPLC ESI-TOF mass spectrometry. Calibration against standards and fitting the isotope patterns were provided by a custom-written LabVIEW programme⁵⁸, detailed in Supplementary Data 1. Source data are provided for panels (b) and (c).